A new record minimum for arctic sea ice

Arctic sea ice reached a new record minimum during the first half of November, according to data from the National Snow and Ice Data Center (Figure 1). The record low ice extent this month is the first extended period of record minimum arctic sea ice since 2007. The new record minimum suggests that the gains in ice seen over the past two years were probably a temporary fluctuation due to normal year-to-year variability in the weather, and that the long-term arctic sea ice decline observed since the 1970s is continuing.

Figure 1. Arctic sea ice extent up to November 16, 2009, compared to the record low year of 2007 and the average from 1979 - 2000. Sea ice extent over the past ten days has fallen below the record minimum observed in 2007. Image credit: National Snow and Ice Data Center.

What caused the new record low?The record low was due to very warm air invading the Arctic during October, in combination with the unusually warm ocean temperatures that have prevailed in the region over the past few decades. The warm air temperatures were primarily the result of an intense series of low pressure systems in the Arctic Ocean, north of Siberia, that worked in concert with a very strong high pressure system north of Alaska to drive warm air from Central Asia poleward over the past six weeks. The strong storms and unusual pressure pattern brought winds of about 5 mph above average to large regions of the Arctic Ocean, which helped break up existing ice and kept ice from freezing as much as usual. With all that warm air flowing into the Arctic, the cold air that was there had to go somewhere else, and that "somewhere else" was North America. The U.S. recorded its 3rd coldest October on record in 2009, thanks to cold air flowing out of the Arctic. The temperature and sea level pressure patterns over the Northern Hemisphere for October (Figure 2) were highly anomalous, with temperatures up to 27°F (15°C) above average over the Arctic Ocean, and sea level pressures up to 11 mb above average. The atmospheric circulation pattern has shifted over the past two weeks, with the result that warm air from Central Asia is no longer being pumped into the Arctic so vigorously, nor is cold air from the Arctic streaming southward into North America. As a result, temperature anomalies in the Arctic are beginning to decline, and sea ice extent later this month will probably rise above the record minimums observed in 2007.

Figure 2. Departure of surface air temperature and surface pressure from average for October 2009. Surface temperatures in the Arctic were up to 27°F (15°C) above average over the Arctic Ocean, due to sea ice loss. The strongest anomalies occurred where sea ice was missing from its usual position, though the entire Arctic was affected. The clockwise flow of air around the anomalously strong high pressure system north of Alaska (labeled "H" in the right-hand image) helped drive a flow of very warm air from Central Asia into the Arctic, and a very cold flow of air out of the Arctic southward into North America. Image credit: NOAA/ESRL.

How will the November sea ice loss affect next summer's sea ice loss?A record 19% of the Arctic sea ice cover this summer in the Arctic was over 2 years old, far below the 1981 - 2000 average of 52%. In the summer of 2009, NASA researcher Ron Kwok and colleagues from the University of Washington in Seattle published satellite data showing that mean winter arctic ice thickness declined by 48% between 1980 and 2008. The loss accelerated over the past five years, with the ice losing 0.68 meters (2.2 feet) of thickness between 2004 and 2008, finishing at 6.2 feet thick. This remarkable thinning was confirmed in May 2009 by the Catlin Arctic Survey, a 9-week, 435 km expedition across the Canadian Arctic led by polar scientist Professor Peter Wadhams of the University of Cambridge. Wadhams' expedition found that most of the route had first year ice just 5.9 feet (1.8 meters) thick. With El Niño conditions crossing from the moderate to strong category over the past two weeks in the Eastern Pacific, the prospects for a much warmer than usual winter in the Arctic have increased, likely setting the stage for continued record or near-record minimum sea ice extent and thickness into next spring. The arctic sea ice will be very vulnerable to a new record minimum next summer if warmer than average temperatures are seen over the Arctic.

Sea ice loss causes stronger storms in the ArcticThe stronger storms over the Arctic Ocean this fall were due, in part, to the loss of sea ice. In a 2009 article titled, Extraordinary September Arctic sea ice reductions and their relationships with storm behavior over 1979-2008, Simmonds and Keay found that September storms over the East Arctic intensified by about 1 mb over the past 30 years and had grown about 50 miles larger in diameter, thanks to all the extra heat energy supplied by more open water due to recent losses in Arctic sea ice. These stronger storms may create a positive feedback loop that will lead to even more sea ice loss: reduced sea ice drives stronger storms, whose winds break up sea ice, creating even more warm water to feed stronger storms with stronger winds, and so on. Now that the arctic sea ice is 48% thinner than 30 years ago, this effect will increase in importance, since thinner ice breaks up more readily in strong winds.

Expect an ice-free Arctic by 2030In a press release put out by the Catlin Arctic Survey, Professor Wadhams said, "The Catlin Arctic Survey data supports the new consensus view--based on seasonal variation of ice extent and thickness, changes in temperatures, winds and especially ice composition--that the Arctic will be ice-free in summer within about 20 years, and that much of the decrease will be happening within 10 years". In their 2009 report on this year's Arctic sea ice minimum, National Snow and Ice Data Center Director and Senior Scientist Dr. Mark Serreze said, "It's nice to see a little recovery over the past couple years, but there's no reason to think that we're headed back to conditions seen back in the 1970s. We still expect to see ice-free summers sometime in the next few decades". At the December 2008 American Geophysical Union (AGU) meeting, the world's largest climate change conference, sea ice expert Dr. Wieslaw Maslowski of the Navy Postgraduate School blamed 60% of the melting during the past decade on heat brought in by ocean currents, and projected that summertime arctic sea ice would completely disappear by 2016. Dr. Jim Overland of NOAA's Pacific Marine Environmental Laboratory was more conservative, projecting a 2030 demise of arctic sea ice. He thought we would be "hanging around where we are for a while", and thought it would take two more unusual summers like the "perfect storm" of 2007 to push the system to an ice-free state.

The consequencesThere were 88 presentations on arctic sea ice at the 2008 AGU conference. None of the presenters expressed the view that the current long-term decline in arctic sea ice was almost entirely natural, or that we can expect the decline to reverse this century. Sea ice experts do blame part of the decline on natural variability in the weather, but we wouldn't be where we are now without the warming caused by human-emitted greenhouse gases. One view (Stroeve et al., 2007) is that human-emitted greenhouse gases are responsible for 47 - 57% of the arctic sea ice loss since 1979. Heat-absorbing black soot from fires and pollution settling on the white ice is thought to also be a significant contributor.

The consensus I heard at the AGU conference among arctic sea ice experts was that the summertime sea ice will be gone by 2030. If they are correct, we can expect a period of significantly accelerated global climate change to begin 10 - 20 years from now. Arctic sea ice is one of the critical components maintaining the stability of our current climate. Once the the ice is gone, the climate will become unstable, with highly unpredictable results. It is true that Earth's past has many examples of warmer climates that evolved due to natural causes where life flourished, and we shouldn't fear the new, stable climate we will eventually arrive at centuries from now. However, life on Earth is adapted to the current climate. The changes that will occur during the transition will be extremely disruptive to Earth's ecosystems and the humans that rely on them for life. If one were to rate the destructive capability of climate change the way we rate hurricanes, I would rate current climate change at the "Invest" or "tropical disturbance" stage--the climate change storm is just beginning to organize. But the coming climate change storm is destined to hit our children with the full fury of intensifying hurricane.

The road to CopenhagenBy some accounts, the future of the world will be at stake this December, when the crucial U.N. Climate Change Conference will be held December 7 - 18 in Copenhagen, Denmark. At that meeting, the leaders of the world will gather to negotiate an agreement to replace the 1997 Kyoto Protocol. The new agreement will be the world's road map for dealing with climate change, and the stakes are huge. Dr. Ricky Rood, author of Wunderground's climate change blog, will be there, and Wunderground has given the University of Michigan a grant to send a student who will also blog for us. I have a number of posts I'm planning in the run-up to Copenhagen, including:

I'll also have an end-of-hurricane season summary on November 30, plus posts on whatever breaking weather stories occur. My next post will be Friday, when I plan to summarize the global weather last month, which was the 2nd - 6th warmest October on record.

Quoting gordydunnot:Please even if you forget that we have cut about half the forest down in the world which sequester carbon turning that into co2 emissions,to actually argue about whether we are putting more co2 in the air than ever before is just ludicrous and tells you why we are in so much peril over the short time. People have always been self interested and the ones who are not, usually end up dead. The problem today is to many people on the planet with to many conflicting self interest. At some point we will end up with a bigger war over limited resources possible taking care of a lot of our problems, although it wont be pretty.

Definitely! Deforestation could possibly be the worst culprit in this. Or at least one of them. These ruthless de-foresters don't realize what they're doing. C02 emissions might not be nearly as big of a concern if we weren't severely reducing the ability to scrub the atmosphere of it daily. Deforestation is just REALLY exacerbating an already alarming situation. I like the message from Klaatu in The Day The Earth Stood Still: "not until faced with extinction will you change."(paraphrased)

Quoting ConchHondros:Just conclude whichever from whatever data...I mean c'mon scientists...really I need to know...I look way better in fall, so a mini ice age would be a boon to my wardrobe...summer not so much, my speedo doesnt fit like it did in the 80's...but like my members only jacket, I wouldnt pass up the chance to sport it...one...more...time :)

Atmo, here's a serious question. can you measure relative humidity with a wet-bulb hygrometer at temps below freezing? i can't seem to find a straight answer on the web with my feeble googling skillz :)

Quoting pearlandaggie:153. sublimation is the process by which ice is directly converted to water vapor without melting the ice. if you leave your ice cubes in the freezer long enough, they shrink because part of the ice has sublimated. it is what is observed when dry ice "melts".

Quoting barryweather:144. One possibility is the effect of the nearby waters. When covered in ice they may reflect enough heat to the thermometers to account for higher temperatures in the earlier data.

I don't think so...I think ice that is below freezing and has a range of temps would have a cooling effect over water that is 33F. The surface stations are not supposed to get sunlight directly, from above or below, but to be shielded from direct insolation and effectively measure the air temp.

Quoting barryweather: As the ice has been absent for longer periods the effect of the water temperature may have kept air temperature more stable/ lower in the later data.

Disclaimer: this is just a theory and is completely unsubstantiated.

That is a possible explanation for the lack of yearly variability! (Not bad, barryweather)

153. sublimation is the process by which ice is directly converted to water vapor without melting the ice. if you leave your ice cubes in the freezer long enough, they shrink because part of the ice has sublimated. it is what is observed when dry ice "melts" (yes, i know dry ice is solid CO2 ;P).

Quoting ConchHondros:Just conclude whichever from whatever data...I mean c'mon scientists...really I need to know...I look way better in fall, so a mini ice age would be a boon to my wardrobe...summer not so much, my speedo doesnt fit like it did in the 80's...but like my members only jacket, I wouldnt pass up the chance to sport it...one...more...time :)

'You could always go out sporting your members only jacket now... people would just look at you funny.

Just conclude whichever from whatever data...I mean c'mon scientists...really I need to know...I look way better in fall, so a mini ice age would be a boon to my wardrobe...summer not so much, my speedo doesnt fit like it did in the 80's...but like my members only jacket, I wouldnt pass up the chance to sport it...one...more...time :)

Thinking about El Nino... Does anyone have a link to the page that has the different SST anomaly graphs for each el nino region? (thinking specifially of the one that has orange for el nino anomalies, and blue for la nina)

Quoting barryweather:128. Still a net rise over time. Alarmism is usually misguided no matter the subject. Just because some view the limited data and conclude that the net global warming over time is caused in part by human C emissions doesn't make them alarmist. Sure some run with it for the sensational appeal that such a story brings, others really do have the worlds best interest at heart as evidenced by many of the comments today. I agree making things cost more arbitrarily isn't a good thing. It is a cost I am willing to take on though, if we can work together to ensure that the world is more efficient/more sustainable for the children we are struggling to feed. Unfortunately, I bet none in this blog will be there to actually make that decision.

By my rough count, the plot in 128 shows the highest average yearly temp in the last 2 decades to be lower than at least 10 other dating back as far as 1880. As in the single highest yearly temp in the 1980s, 1990s, or 2000s is lower than a lot of the historical records and does not appear remarkable.

That is a net rise over time only if you start in the 1980s.

Still want to know how it is that the Arctic ice is at some tipping point or is at some spectacular lowest extent without Arctic surface obs picking up any real warming over obs from 30, 60, or 100 years ago.

144. One possibility is the effect of the nearby waters. When covered in ice they may reflect enough heat to the thermometers to account for higher temperatures in the earlier data. As the ice has been absent for longer periods the effect of the water temperature may have kept air temperature more stable/ lower in the later data.

128. Still a net rise over time. Alarmism is usually misguided no matter the subject. Just because some view the limited data and conclude that the net global warming over time is caused in part by human C emissions doesn't make them alarmist. Sure some run with it for the sensational appeal that such a story brings, others really do have the worlds best interest at heart as evidenced by many of the comments today. I agree making things cost more arbitrarily isn't a good thing. It is a cost I am willing to take on though, if we can work together to ensure that the world is more efficient/more sustainable for the children we are struggling to feed. Unfortunately, I bet none in this blog will be there to actually make that decision.

Quoting jeffs713:For those using individual station plots as "proof" for/against GW... consider that the GW theory is using GLOBAL averages, not individual stations. Also, just like El Nino, warming on a global scale will have varying impacts, depending on local and regional topography. (Some areas will become drier, some wetter. Some areas will become warmer overall, some colder, and some will just have more extremes)

This is completely true. Just trying to work out in my own head how it could be that the Arctic sea ice extend is so remarkable when the available surface stations ringing the area show nothing to suggest any remarkable warming.

133. have i missed something...has someone stated that data from one location disproves the AGW hypothesis? seems like the discussion has centered more around data quality and siting issues as well as the inability to reconcile certain data anomalies...

I have seen something on the History(?) channel that talked of a ~90 foot sea level rise since the time of the Phoenicians and talked about all of the historical sites that are well under water, given the sea faring behaviors and port cities, etc. Haven't found much in a science study detailing the rise or it's cause...anyone?